<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>a元素的伪类</title>
    <style>
         a:visited{
            color: green;
        }
      
        a:hover{
            color: blue;
            font-size: 30px;
        }
        a:active{
            color:black;
        }
        a:link{
            color: red;
        }
    </style>
</head>
<body>
    <a href="https://www.baidu.com">访问过的链接</a>
    <br><br>
    <a href="https://www.baidu123.com">没访问过的链接</a>
</body>
</html>